LC Responses/ZW2b

4. We want to see owl:rational taken out from OWL 2 RL. It is unclear how useful this datatype is to our users.

8. The justification for the [un]supported datatypes is not complete. For example, OWL 2 RL does not allow xsd:positiveInteger which does not appear to violate the stated justification "the intersection of the value spaces of any set of these datatypes is either empty or infinite"

Your message contains multiple sections, affecting more than one
document, and will thus generate multiple replies. This response
is for sections 4 and 8 about the datatypes in OWL 2 RL.

We have adjusted the datatypes of OWL 2 RL to include those XML Schema
datatypes that are derived from xsd:string and xsd:integer, including
xsd:positiveInteger. These were excluded from OWL 2 RL because of a
mistaken analogy with OWL 2 EL and OWL 2 QL, namely that intersection of
value spaces must be either empty or infinite to maintain the desired
properties of the profile. It turns out that this is not needed in OWL
2 RL to obtain its desired computational properties. As any OWL 2 RL
tool has to process xsd: string and xsd:integer, the added
implementation burden to support these datatypes is negligible.

The situation with owl:rational and owl:real is different. The working
group has received complaints that implementing
these datatypes may require significant effort on top of a rule
reasoner. Therefore owl:rational and owl:real have been removed from
OWL 2 RL. This possibility was mentioned in Feature At Risk #2.

The diffs for these changes can be found at
.....

The working group notes that Oracle has also brought up concerns with
the treatment of xsd:float and xsd:double. These two datatypes are not
currently part of OWL 2 RL. If this situation changes the working
group will communicate with you.

Please acknowledge receipt of this email to
<mailto:public-owl-comments@w3.org> (replying to this email should
suffice). In your acknowledgment please let us know whether or not you
are satisfied with the working group's response to your comment.

Regards,
Peter F. Patel-Schneider
on behalf of the W3C OWL Working Group

Your message contains multiple sections, affecting more than one
document, and will thus generate multiple replies. This response
is for sections 4 and 8 about the datatypes in OWL 2 RL.

We have adjusted the datatypes of OWL 2 RL to include those XML Schema
datatypes that are derived from xsd:string and xsd:integer, including
xsd:positiveInteger, plus xsd:boolean. These were excluded from OWL 2 RL because of a
mistaken analogy with OWL 2 EL and OWL 2 QL, namely that intersection of
value spaces must be either empty or infinite to maintain the desired
properties of the profile. It turns out that this is not needed in OWL
2 RL to obtain its desired computational properties. As any OWL 2 RL
tool has to process xsd: string and xsd:integer, the added
implementation burden to support these datatypes is negligible.

The situation with owl:rational and owl:real is different. The working
group has received complaints that implementing
these datatypes may require significant effort on top of a rule
reasoner. Therefore owl:rational and owl:real have been removed from
OWL 2 RL. This possibility was mentioned in Feature At Risk #2.

The working group notes that Oracle has also brought up concerns with
the treatment of xsd:float and xsd:double. These two datatypes are not
currently part of OWL 2 RL. If this situation changes the working
group will communicate with you.

Please acknowledge receipt of this email to
<mailto:public-owl-comments@w3.org> (replying to this email should
suffice). In your acknowledgment please let us know whether or not you
are satisfied with the working group's response to your comment.

Regards,
Peter F. Patel-Schneider
on behalf of the W3C OWL Working Group